This invention relates to a shaft seal and, more particularly, to a sealing assembly for effecting a sealing joint between relatively rotatable elements which include a stationary element and a rotatable shaft passing through the stationary element.
It continuously is a problem to seal the opening in a wall or the like of various types of machinery through which a rotatable shaft protrudes in such a manner as to prevent leakage or loss of pressure and at the same time to avoid undue shaft friction which generates heat, causes loss of power and may even lead to injury to the shaft or the associated machinery, or both. One method of effecting a seal at a joint between a stationary element and a rotatable shaft has been through the use of packing, stuffing, or the like. However, packing or stuffing causes considerable friction on the shaft. The present invention is directed to a sealing assembly which does not utilize packing or stuffing and thereby eliminates the friction caused thereby so that the rotatable shaft can operate at faster speeds while also adding to the operative life of the shaft. Other sealing joints have utilized O-rings. However, it always is a problem in providing a proper material for the O-rings due to the wear thereon when utilized with shafts that operate at high speeds. These problems are of particular magnitude in the chemical industry or the nuclear field where very efficient seals must be provided between stationary and rotatable members which cannot be provided by packing or stuffing materials. Shaft speeds often range in the area of 3,600 r.p.m.'s or greater.
In certain applications, particularly where the machinery or equipment which is being sealed in large and heavy, or where it would be particularly inconvenient for other reasons for the equipment to be stripped or dismantled to replace conventional mechanical seals, it is desirable that the parts of the mechanical seals which are subject to wear be split so that they can be easily mounted about the shaft and readily disassembled therefrom for repair or replacement purposes. The features of the present invention are particularly adapted for use in a split-type seal which can be easily assembled about the rotatable shaft and disassembled therefrom without interfering with the positioning or mounting of the rotatable shaft as well as the stationary element with which it is associated.
In addition, it is a problem with seals of the character described to maintain a complete seal at all times completely about the rotatable shaft. During operation, the seals become worn or deteriorated and the wear and deterioration often times is non-uniform circumferentially about the shaft. This is true because of many reasons such as misalignment of the rotatable shaft with respect to the stationary machinery or equipment with which it is used, or due to other factors. It is highly desirable to provide a sealing assembly for the rotatable shaft which is selectively adjustable angularly or circumferentially about the shaft so as to accommodate non-uniform wearing or deterioration of the seal parts, such as the sealing ring.
This invention is directed to solving the above and other problems while providing a new and improved seal of the character described not heretofore available.